a manual camera really only have to be changed after ten minutes or so, or when changing location. Nevertheless, an exposure control display in the viewfinder was considered very early at Rollei, but an analog display was discarded for limited space reasons, and light emitting diodes were not available at the time.) So not until summer of 1979 were the Rollei 35 TE and Rollei 35 SE released to the market. As the electronic exposure meter needed more power, a larger battery, of type PX-27 with 5.6 volts, was placed where the former instrument movement was mounted, The electronic circuit was built into the former battery compartment. Unlike the Rollei 35 LED the shutter position and aperture control settings were transferred, without any electrical contact wear and tear, using a differential gear turning a variable density filter in front of the CdS light sensor. The release button activated the light meter, when slightly depressed. Three LEDs in the viewfinder indicate the correct exposure. This system worked perfectly, yet earlier models are more in demand today. Use of the Rollei 35 today The Rollei 35, Rollei 35 S and Rollei 35 T use a MR-9 mercury-battery with 1.35 volts, which is no longer produced due to environmental considerations. But there are alternatives available. A zinc-air cell also provides 1.35 volts, yet with a limited usage time of 1 to 6 months after first activation depending on the design of the cell. Otherwise the light meter may be adjusted for use of mercury-free silver-oxide batteries. Without adjusting, the higher voltage of 1.55 volts would lead to overexposure by 2 to 3 aperture steps. An adapter to fit the smaller silver-oxide battery to the battery compartment is required. The closest one in size to the original MR-9 would be SR-44. Alkaline batteries such as the LR-9 a.k.a. PX 625U can not be used, since alkaline cells do not provide constant voltage and will lead to underexposure after becoming half-depleted. Another option is the adaption of the camera for 1,5 V batteries by a Rollei workshop. Technical data Standard models Rollei 35 – Original model Made from 1966 until August 1974 Lens: Tessar f/3.5, 40 mm, but many items from July 1972 to April 1973 with S-Xenar (made by Schneider) Light meter: Battery powered, using CdS photoresistor Initial retail price: chrome 487 DM, black 537 DM Retail price of items made in Singapore: chrome